The present invention is related to a film probe for testing liquid crystal display, and more particularly to a contact-type film probe. Signal transmission lines and contact conductive layers are respectively disposed on two faces of the substrate for prolonging using life of the contact-type film probe.
In a conventional contact-type soft film probe structure, multiple one-to-one straight film probes are directly made on a specific tool according to the wire layout of a liquid crystal display. The probes directly contact with the wires of the liquid crystal display. After contacted, the signal will be input via the probes to activate the liquid crystal display. According to the state of display, it can be judged whether the quality of the liquid crystal display is good or bad.
FIGS. 3 and 4 show a conventional contact-type soft film probe. Multiple signal lines 82 are arranged on one face of a plastic substrate 81 according to wire layout of a liquid crystal display. A contact conductive layer 83 is disposed at one end of each signal line 82 to form a probe. The other section of the signal line 82 free from the contact conductive layer 83 is coated with an insulating layer 84.
The thickness of each layer of the film probe is in the grade of micron so that the thickness of the film probe as a whole is still very thin. Accordingly, when contacting the film probe with the wire 91 of the liquid crystal display 9 as shown in FIG. 5, it is necessary to slightly apply a pressure onto the probe, whereby the contact conductive layers 83 of the film probe can truly contact with the wires 91 of the liquid crystal display. However, during contacting, the contact conductive layers 83 will frictionally contact with the wires 91 of the liquid crystal display. Especially, the edges and corners of the wires 91 of the liquid crystal display tend to partially over-wear the contact conductive layers 83 and signal lines 82. This may cut off the contact conductive layers 83 and the signal lines 82. As a result, the signal cannot be normally transmitted to the wires of the liquid crystal display. This will make the liquid crystal display unable to display pictures or lead to poor display of the pictures. Accordingly, the test result of the liquid crystal display will be affected. Furthermore, in the case that the contact conductive layers 83 are worn out or cut off, the using life of the film probe will be shortened and the cost will be increased.